A walking safari through Kenya, a journey through the Himalayas, a "sail-by-night, bicycle-by-day" package in the Caribbean Islands or a whirlwind, five-day pass through Paris, with a stay at a five-star hotel, are among the tours assembled by travel organizations for this winter and spring.

A sampling of some unusual packages and itineraries for the upcoming months follows:Mountain Trekking: A 25-day package "eco-tour" goes through the Himalayas, from Kathmandu, Nepal, to Gangtok in Skiiim, Darjeeling in West Bengal and the kingdom of Bhutan. A naturalist tour guide accompanies the group throughout, and the land cost of $5,750 a person, double, includes first-class accommodations, all meals, sightseeing, transfers, taxes and tips. Departure date is March 8. Sponsor is Questers, (800) 468-8668.

Bike 'n' Cruise: Here's an expedient way to work off the calories that mount up on a cruise. The tours are organized by Emmett Travel in Portland, Ore., in conjunction with the Portland Wheelmen Touring Club and Norwegian Cruise Lines. The itinerary includes sailings out of San Juan, Puerto Rico, aboard the Starward and Skyward vessels, plus daily guided rides exploring islands such as Aruba, Curacao, Martinique, St. Martin, Tortola and Antigua. Prices start at $1,157 per person, double, including airfare and meals. Winter departure dates are Feb. 2 and 9 and March 16. Emmett Travel is at (800) 333-5190.

Rocket to Russia: You could be stompin' at the Savoy - Moscow's five-star Savoy Hotel - on just about any Saturday night this winter or spring on FinnWay's weekend-in-Moscow package. Prices are $845 to $1,245 per person. The recently renovated Savoy is one of the Soviet Union's most luxurious hotels. Call FinnWay at (800) 526-4927.

Rain Foresting: Eco-tourism, wet and wild. Breakaway Adventure Travel has scheduled six 10-day tours of the Amazon rain forest in 1991.

The trips, warns the agency, are not "for typical tourists; a serious interest in studying the rain forest and its inhabitants is a prerequisite."

Conditions are ... well, primitive, and participants "should have camping experience as well as sensitivity to cultural differences."

The explorations begin from Caracas, Venezuela; departure dates are Feb. 25, April 15, June 17, Aug. 5, Oct. 14 and Dec. 2. The tour cost is $1,890 per person, plus airfare. Contact Breakaway at (800) 955-5635.